U.S. Pat. No. 4,250,293 discloses a latent curing agent which is a salt of bisphenol-A (BPA) and an amine of dimethylaminopropylamines (DMAPAs), and an epoxy powder coating composition to which the same is applied.
Further, U.S. Pat. No. 6,184,273 discloses a coating composition having a latent curing agent produced by the reaction of alicyclic anhydrides (e.g., phthalic anhydride) and polyamine, and a carbonated epoxy resin.
In addition, U.S. Pat. No. 6,592,994 discloses a clear coating epoxy powder composition which uses a dicyandiamide (DICY) latent curing agent.
However, the latent curing agents disclosed in the aforementioned documents may show a poor coating workability due to insufficient latency. Although the dicyandiamide exhibits relatively excellent latency due to the high melting point, it may cause a deteriorated bending property when applied to a rebar powder coating.